Hi,

The D spec says: "If it(aggregation expression) is an associative array, the
order of the elements is undefined."
How can I sort an associative array so that the elements in a foreach loop are
ordered then?

-Kay

On Thu, 3 Feb 2005 03:10:56 +0000 (UTC), Kay <Kay_member@pathlink.com> wrote:
> The D spec says: "If it(aggregation expression) is an associative array, the
> order of the elements is undefined."
> How can I sort an associative array so that the elements in a foreach loop are
> ordered then?

This might do what you want:

# import std.stdio;
#
# int main(char[][] args) {
# 	int[char[]] AA;
# 	char[][] tmp;
# 		
# 	AA["d"] = 3;
# 	AA["f"] = 5;
# 	AA["a"] = 0;
# 	AA["c"] = 2;
# 	AA["b"] = 1;
# 	AA["e"] = 4;
# 	
# 	foreach(char[] key; AA.keys)
# 		tmp ~= key;
# 	tmp.sort;
# 	
# 	foreach(char[] key; tmp)
# 		writefln(key," = ",AA[key]);
# 		
# 	return 0;
# }

Regan

If you want to sort the array you should follow Regean suggestion.
But if you want to preserve the insertion order, you should give a look at
Ben Hinkle MinTL: LinkedAA container.

Miguel Ferreira Simões

Give a look at MinTL there is also a SortedAA container.

Miguel

In article <cts4nv$1l7u$1@digitaldaemon.com>, Kay says...
>
>Hi,
>
>The D spec says: "If it(aggregation expression) is an associative array, the
>order of the elements is undefined."
>How can I sort an associative array so that the elements in a foreach loop are
>ordered then?
>
>-Kay

There is an implementation of an associative array that stores its elements in a sorted order (determined either by the natural key comparison or by a user supplied comparison or by insertion order) in the MinTL library http://home.comcast.net/~benhinkle/mintl/. In particular see the doc for SortedAA and LinkedAA: http://home.comcast.net/~benhinkle/mintl/#sortedaa and http://home.comcast.net/~benhinkle/mintl/#linkedaa. The SortedAA class uses red-black trees which is the same as most C++ implementations of a "map".

I can't tell if you want to sort the items after you insert them or maintain the array in sorted order from the beginning. The MinTL arrays require you to know the order you want before you start inserting anything.

good luck,
-Ben

I think you can skip the tmp step right, and just do

foreach (char [] key;AA.keys.sort )
{}

?

Charlie
"Regan Heath" <regan@netwin.co.nz> wrote in message
news:opsllqsqna23k2f5@ally...
> On Thu, 3 Feb 2005 03:10:56 +0000 (UTC), Kay <Kay_member@pathlink.com>
> wrote:
> > The D spec says: "If it(aggregation expression) is an associative array,
> > the
> > order of the elements is undefined."
> > How can I sort an associative array so that the elements in a foreach
> > loop are
> > ordered then?
>
> This might do what you want:
>
> # import std.stdio;
> #
> # int main(char[][] args) {
> # int[char[]] AA;
> # char[][] tmp;
> #
> # AA["d"] = 3;
> # AA["f"] = 5;
> # AA["a"] = 0;
> # AA["c"] = 2;
> # AA["b"] = 1;
> # AA["e"] = 4;
> #
> # foreach(char[] key; AA.keys)
> # tmp ~= key;
> # tmp.sort;
> #
> # foreach(char[] key; tmp)
> # writefln(key," = ",AA[key]);
> #
> # return 0;
> # }
>
> Regan

On Wed, 2 Feb 2005 22:18:23 -0600, Charles <no@email.com> wrote:
> I think you can skip the tmp step right, and just do
>
> foreach (char [] key;AA.keys.sort )
> {}

Godd idea, you're probably right. I assume .sort returns a copy of the array?

> Charlie
> "Regan Heath" <regan@netwin.co.nz> wrote in message
> news:opsllqsqna23k2f5@ally...
>> On Thu, 3 Feb 2005 03:10:56 +0000 (UTC), Kay <Kay_member@pathlink.com>
>> wrote:
>> > The D spec says: "If it(aggregation expression) is an associative  
>> array,
>> > the
>> > order of the elements is undefined."
>> > How can I sort an associative array so that the elements in a foreach
>> > loop are
>> > ordered then?
>>
>> This might do what you want:
>>
>> # import std.stdio;
>> #
>> # int main(char[][] args) {
>> # int[char[]] AA;
>> # char[][] tmp;
>> #
>> # AA["d"] = 3;
>> # AA["f"] = 5;
>> # AA["a"] = 0;
>> # AA["c"] = 2;
>> # AA["b"] = 1;
>> # AA["e"] = 4;
>> #
>> # foreach(char[] key; AA.keys)
>> # tmp ~= key;
>> # tmp.sort;
>> #
>> # foreach(char[] key; tmp)
>> # writefln(key," = ",AA[key]);
>> #
>> # return 0;
>> # }
>>
>> Regan
>
>

Kay wrote:

[...]
> How can I sort an associative array so that the elements in a foreach loop are ordered then?

Do you have an order at all?

-manfred

Regan Heath wrote:
> On Wed, 2 Feb 2005 22:18:23 -0600, Charles <no@email.com> wrote:
> 
>> I think you can skip the tmp step right, and just do
>>
>> foreach (char [] key;AA.keys.sort )
>> {}
> 
> 
> Godd idea, you're probably right. I assume .sort returns a copy of the  array?

No, it sorts it in place.  So my preferred way of doing things is this:

foreach(char[] key; AA.keys.dup.sort)
	{ ... }